When does a startup need to invest in HR software?

Most startups can manage with spreadsheets and a payroll service up to about 15 employees. By 25–30 employees, inconsistent onboarding, manual PTO tracking, and compliance risks make HRIS software worth the investment. Key triggers: you're hiring faster than 1–2 people/month, you've had a compliance issue, or your founders/ops team is spending more than 5 hours/week on manual HR administration.